Assessment of MSW management strategies for mid-sized metropolitan areas for developing countries
Name: José Carlos Martins Ramalho
Type: PhD thesis
Publication date: 27/06/2023
Advisor:
Name |
Role |
|---|---|
| João Luiz Calmon Nogueira da Gama | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| Diogo Appel Colvero | Co advisor * |
| Diogo Costa Buarque | Internal Examiner * |
| João Luiz Calmon Nogueira da Gama | Advisor * |
| Rodrigo de Alvarenga Rosa | Internal Examiner * |
Summary: This goal of this thesis was to conduct an environmental and economic analysis of different
MSW management strategies proposed for the municipalities of Great Vitória Metropolitan
Region, in Espírito Santo State, Brazil. Even though the situation in this region is overall
better than in the rest of the country, because the dumps were replaced by licensed landfills,
the proposed diversion targets by the Brazilian Solid Waste Plan are a long way from being
met. For that reason, the proposed technological road maps included options for biowaste
treatments, namely open and closed composting, anaerobic digestion with energy recovery
and biomethane production, and recycling. As for commingled waste disposal, incineration
with energy recovery was put against landfilling. So, the first part of the study focused on
the use of biomethane from anaerobic digestion by waste collection and transport vehicles
compared to the current diesel counterparts. The results shown that using biomethane is a
much better option, with about one tenth of environmental impacts of diesel. Conversely,
both the second and third chapters analyzed the entire waste management system from an
environmental and economic perspective, respectively. Overall, to abide the most ambitious
diversion targets ensures the best results from both perspectives, i.e., to recycle and treat
the biowaste as much as possible. As for the ways to achieve this, anaerobic digestion with
biomethane production has the best environmental performance, even though it is more
costly. However, if a social project instead of a profit-oriented one is foreseen, the service
cost for the citizens increases only so slightly. The scenarios with incineration were
penalized for their performance in toxicity impact categories, but were better than landfills
regarding climate change. Additionally, the high investment costs may push investors away
from incineration, since the current landfills are recent and one has energy recovery.
Nonetheless, the service fees can actually decrease with incineration, again if no profit is
sought in the investments. Finally, the focus of management should follow the waste
hierarchy instead being sent directly to final disposal, because the fraction of biowaste
represents half of the total municipal solid waste in the studies area, and recycling creates
opportunities for including pickers in the materials recovery facilities.
